Compared to prior in [1]} or [2]}, which considered Laplace prior that is not differentiable at its median on off-diagonal entries, prior in (7) is always twice continuously differentiable. Thus, if we are to compute the posterior model probabilities of \(\mathcal {Z}\)  using Laplace approximation, prior on off-diagonal entries in (7) takes the advantage over Laplace prior because it is twice continuously differentiable and we do not need to check the regularity of the model.
